Circuit patterns are produced by a number of manners, including screen printing. Typically, in a screen printer a screen having a printing pattern, is disposed over an object to be printed. Printing ink is coated onto the screen, and then spread by the use of a wiper also disposed over a top surface of the screen. The wiper assists in the printing of the pattern onto the object to be printed. One example of a conventional screen printer is illustrated in U.S. Pat. No. 5,176,076 issued to Azuma on Jan. 5, 1993.
Typical screen printers, however, can result in excessive material costs. The printing paste is disposed on the screen for each application and can dry out and solidify rapidly due to the repeated working of the paste, as well as its exposure to air. In addition, cleaning issues also occur as the paste dries on the screen in between uses. Other areas which challenge conventional screen printers is uniformity in the thickness of application of the printing medium. The printing paste undergoes changes such as solidification, oxidation, etc. from being left on the screen when not in operation, which results in an undesirable printing effect. Thus, the paste must be removed from the screen and replaced with new printing paste. Replacement of the paste requires additional material and additional labor. Furthermore, solidification of the paste can result in variations in thicknesses of the paste application leading to excessive use of the paste, thereby further adding to the overall cost of the unit.
Accordingly, what is needed is a screen printer which overcomes the above waste and cleaning problems. What is further needed is a screen printer which assists in preventing the drying of printing paste between applications. What is also needed is a screen printer which provides a uniform application of material.